The United States and Japan will step up their defence cooperation to deal with the threat from nuclear-armed North Korea as tensions in East Asia remain high, officials from the two allies said on Thursday.

Election won't be called today, PM Malcolm Turnbull says

Prime Minister Malcolm Turnbull has affirmed that he'll be visiting the Governor-General in the next few days to call the election.

But he won't be making the short drive to see Governor-General Peter Cosgrove at Government House on Friday.

He said that was because the Senate was still sitting, with a full day of estimates committee hearings, quizzing ministers and officials about measures announced in the budget on Tuesday.

"We don't want to disturb that. But I will be visiting the Governor-General shortly and there will be an election on July 2," he told Sky News.

Mr Turnbull said this would be a critical choice for Australia.

"The question will be who do you trust to ensure that our economy transitions successfully from the mining construction boom to one where we take advantage of the great opportunities of the 21st century," he said.

Opposition Leader Bill Shorten said in 58 days Australians would have a choice.